Notebook computers generally have one or more interface slots on the backside or lateral sides to couple with connectors of different peripheral devices. When the interface slot is not in use, a lid to prevent external dusts from smearing the interface slot usually covers it.
There are many types of lid mechanisms to cover the interface slot and provide a dust-guarding function. FIG. 1 illustrates a lid 1 for a conventional notebook computer. The lid 1 has a latch structure 3. When in use, push the latch structure 3 to unlatch the case 5, the lid 1 may be turned outwards to expose the interface slot. When not in use, swing the lid 1 about stub shafts to cover the interface slot and move the latch structure 3 to latch on the case 5. Such a structure has a complicated structure that includes many delicate elements such as springs. It is not sturdy and cannot withstand the strong impact of external forces. Damage or dislocation of the springs often occurs. It does not have much shock-absorption capability. Moreover, it uses a sliding mechanism, which cannot prevent moisture from seeping into the interface slot when closed. Hence it also cannot provide a satisfactory waterproof function.
Another conventional lid structure for the interface slot of notebook computers (R.O.C. patent publication No. 449244) is shown in FIG. 2. It has a lid 7 located on an input/output interface opening 9 of one side of the computer case. When the interface slot 11 is not in use, the lid 7 is turned about a pintle 13 and bulged elements 17 located on L-shape plates 15 of the lid 7 are moved to couple with latch cavities 19 formed on two sides of the interface slot 11 in a latched position. On the contrary, the lid 7 is opened when pulled forcefully. While it provides some degree of dust-guarding, it does not help much in the waterproof and shock-absorption functions.